100s: where are the springs up front? (1 Viewer)

[e9999]

so, the 100s have an IFS. Went under. No spring to be seen. And the shocks look like regular ones. Only gizmo I saw down there that looked like it could have helped keep the truck up is some sort of torsion bar. But surely this little guy couldn't do all the job by itself, or could it? And will it last?
Or are these levitating cuz they are the trucks of gods?
uh?
Eric

 

[firetruck41]

My 1996 T-100 4WD used a torsion bar IFS IIRC, it could be the case for the 100 series ???

 

[Beowulf]

Eric,
The 100 series IFS trucks have torsion bars (it should have 2). I believe Chrysler invented these back in the 50s but that could be due to some memory loss in the 60s. They can be cranked a bit to gain some lift but otherwise you're stuck with them.
-B-

 

[Jonathan_Ferguson]

I believe Chrysler invented these back in the 50s but that could be due to some memory loss in the 60s.

Parnhard et Lavasor invented the Torsion Bar, And were fitted to one of their Models in 1932. - Actally had Torsion Bars on the front and rear. 8)
Panhard et Lavasor also invented the Panhard Rod and Manual Gearbox(Same as they are today).

 

[the shed guy]

A coil spring is just a torsion bar, in a circle, instead of straight.

 

[Beowulf]

Thanks Jonathan.

That just further proves that the big companies try to convince the unwitting mercan public that they invented everything. ('cept the Internet... a politician invented that.)

-B-

 

[Jim_Chow]

Toyota must have had some reason for going w/ t-bars on the 100 series. The t-bars are used on 1st and 2nd gen IFS 4runners/mini-pickups ('86-95) as well as overseas hilux's ('98+). These rigs also have 1-ton rated, fully-boxed ladder frames, with the only thing keeping them from having 1-ton capacity is a lack of a FF rear axle (T100 is also 1-ton rated). OTOH, the tundra/Tacoma, which are only sold in the N. American market, don't have fully boxed frames that can withstand 1-ton loads, even w/ a FF axle. The only exception I've seen (maybe) is a dually tundra owned by Toyota America in Torrance. Toyota must have some evidence that t-bars up front are better than coils w/ IFS for offroad.

 

[e9999]

thanks all
Darren, your observation on the t-bar vs coil is interesting.
My limited intuition would not have led me believe that a t-bar of this size would have had the durability and strength, but what do I know about steel...?
I take it that if Toy has used them since '86 they should be plenty strong eh!
Oh well, one learns every day
thanks
eric

 

[the shed guy]

I personally prefer the coil set up like the tecoma, and 90 series prado and 120 series here.

Pity the 100 didnt go that way.

 

[cary]

As someone already said, a torsion bar is simply a straight spring. They are widely used by Toyota, Mercedes in the M class, Chevy/GM on the full size pickups and SUV's, Nissan. The advantage of a torsion bar is packaging versus a coil spring. As far as how long they last, the torsion bars in my 1991 Nissan pathfinder are still fine. One big advantage of the bars is as they sag, you can adjust them to compensate. Try that with coils.

Cary

 

[cruiserman]

[quote author=Jim_Chow link=board=2;threadid=5998;start=msg48111#msg48111 date=1065502205]
Toyota must have had some reason for going w/ t-bars on the 100 series. The t-bars are used on 1st and 2nd gen IFS 4runners/mini-pickups ('86-95) as well as overseas hilux's ('98+). These rigs also have 1-ton rated, fully-boxed ladder frames, with the only thing keeping them from having 1-ton capacity is a lack of a FF rear axle (T100 is also 1-ton rated). OTOH, the tundra/Tacoma, which are only sold in the N. American market, don't have fully boxed frames that can withstand 1-ton loads, even w/ a FF axle. The only exception I've seen (maybe) is a dually tundra owned by Toyota America in Torrance. Toyota must have some evidence that t-bars up front are better than coils w/ IFS for offroad.
[/quote]

Coil over setup with double wishbone is used on the Tacoma.

 

[Jim_Chow]

[quote author=cruiserman link=board=2;threadid=5998;start=msg48254#msg48254 date=1065541325]
Coil over setup with double wishbone is used on the Tacoma.
[/quote]

That was the root of the point I was trying to make...why did toyota switch to a coil IFS system on the Taco just for the N. American market whereas the hilux's overseas (and 100's and, I think, the newer prado) have t-bars, including those sold in Oz and S. Africa? It's known that toyotas designated for overseas markets are worked hard and for many years longer than their US counterparts, often well over their rated capacity (I've seen old 2wd hilux's in Thailand w/ half a dozen large hogs in the back in steel cages, also ones w/ bales of hay stacked up 15 ft; they were running 9-leaf packs in the rear). And we know that the Toyotas designed for the US market are really intended to be driven on the road...

 

[cruiserman]

And we know that the Toyotas designed for the US market are really intended to be driven on the road...

You answered your own question . . .

Rack and pinion steering, too :'(.

 

[Jim_Chow]

[quote author=cruiserman link=board=2;threadid=5998;start=msg48286#msg48286 date=1065545027]
You answered your own question . . .

Rack and pinion steering, too :'(.
[/quote]

Oh, yeah, forgot about that! In fact, I looked at a hilux tiger crewcab turbo diesel (3.0L D4D) in Thailand last year. The chassis is identical to that of the US-market '86-88 4runners except backwards for the right-hand drive (fully boxed frame, front t-bars, rear leafs, recirc. ball steering) except the idler arm has been beefed up, the t-case is the chain-drive case instead of the geared one, and there are more leafs in the leaf packs. Even the exhaust, which exits the engine on the right side, bends across in front of the t-case to exit on the same (left) side. I guess in this case, the US proved to be a good testing ground for that platform, which replaced the live front axle/leaf spring model overseas around '98.

You'd think it would have been cheaper for Toyota to just import the hilux as-is instead of engineering a different vehicle for this country. I guess the decision could have been political, as the Taco is made by UAW workers at some GM-related plant in Fremont, CA.

 

[cruiserman]

Surprisingly enough, I think the USA is a testing ground for making things lighter and softer .

 

[Gumby]

the only real problem I have seen with torsion bars is when the rear mount rusts away and the bar twists free of the crossmember. Lots of 70s chyrslers died that way.

 

[Gumby]

Oh, and t-bars have limited sag as opposed to coils that droop forever is they are not captured.

 

[IdahoDoug]

Wouldn't a Tbar have more available sag, since you can both adjust and re-index them?

IdahoDoug

 

[Gumby]

Nothing limits a coil sag other than the shocks. T-bars are fixed. They will only droop as far as they will twist.

maybe we are talking different sags. The at-rest alignment measurement known as sag would be more adjustable with t-bars. The amount the suspension droops when unloaded was what I was refering to.

 

[IdahoDoug]

Oh, gotcha. You're talking sag/droop like compression/extension.

Yeah, I'm not too sure that the coil would have any advantage in this way. Interestingly, when you compress a coil, you are twisting the spring rod in the exact same way as if it were straight. Let it sag and you'll still be limited by the amount of "untwisting" just like a straight torsion type spring.

Somehow, a coil "looks" more supple and competent to my eye, but AFAIK the action is exactly the same - just a packaging issue to decide between the formats (coil vs straight).

IdahoDoug